1. Field of the Invention
The invention relates to connectors for tubing and, more particularly, to connectors for (a) attaching corrugated tubing to other structures without special modification of the tubing and (b) securing a covering of braided wire in position about the tubing.
2. Description of the Prior Art
Although various types of connectors for tubing are known, these known connectors have suffered from several drawbacks. One of the most important drawbacks relates to a need to modify the ends of tubing in order to connect the tubing to other structures. For example, in the case of well-known riser tubes used in residential plumbing systems, one end of a corrugated tube must be formed without corrugations. The uncorrugated, straight-walled end section is adapted to receive a nut and an annular ferrule. The end section with ferrule attached then can be inserted within the inner diameter of an existing fitting and the nut can be tightened about the tube so as to compress the ferrule within the fitting. Upon continued tightening of the nut, the ferrule or the tube, or both, will be deformed and a fluid-tight seal will be created. In many circumstances, however, a consumer installing such a tube may improperly tighten the nut if care is not taken, and the connector often will leak.
The other end of a typical riser tube includes an upset portion having an annular flange for attachment to existing plumbing fixtures. Although connection of such an upset end portion to a fitting is relatively easy, such a connection by definition requires that the tube be manufactured with an upset end portion. Consequently, the cost of producing the tube is higher than desired.
The requirement that both ends of a riser tube be specially configured necessarily limits the lengths of tubes which can be used by consumers. That is, because very few individuals doing plumbing work possess the equipment needed to modify the ends of a corrugated tube to permit it to be used with existing connectors, corrugated tubing having appropriately configured ends must be manufactured in discreet lengths so that consumers can select a length of tubing appropriate for the job at hand. Obviously, the expense of manufacturing and maintaining an inventory of otherwise identical tubing, differing only in length, presents a considerable difficulty to manufacturers and distributors. It also presents a difficulty to the consumer who must carefully choose the proper length of tubing when making a purchase.
Yet an additional problem with corrugated tubing relates to the performance of the tubing itself as regards vibration and internal pressures. In certain applications, corrugated tubing is provided with a covering of braided wire rigidly secured to connectors attached to the tubing at each end. Assuming that the braided wire is of proper length and is rigidly secured to the connectors, the wire will prevent tube elongation under high internal pressure. The wire also will dampen vibration in the tube and can provide some protection for the tube from such undesirable influences as abrasion and impact.
A problem with prior corrugated tubing employing braided wire has been the attachment between the wire and the connectors carried by the ends of the tubing. In the past, it has been necessary to weld the wire braid to the connectors. Welding is undesirable because it is timeconsuming, is difficult to carry out on a production basis, and it may adversely affect the strength characteristics of the tubing or the connectors. In addition, welding the wire to the connectors reduces the available materials from which the connectors, the tubing, or the wire can be chosen. Desirably, a connector for tubing would include provisions for securing a covering of braided wire or other material to the connector and/or the end of the tubing without the need for welding.
In view of the foregoing difficulties, it is an object of the present invention to provide a connector for corrugated tubing in which no special modification of the ends of the tubing are required to effect a fluid-tight seal.
It is yet another object of the invention to provide a connector for corrugated tubing whereby the tubing can be cut to length by the user of the tubing and the connector can be fitted to the end of the tubing at the job site.
It is yet another object of the invention to provide a connector for corrugated tubing by which a covering of braided wire or other material can be quickly secured in place about the tubing without the need to weld the covering to either the connector or the tubing.